In vivo sensors are non invasive tools used in diagnosis of diverse body systems. For example, ingestible devices may be used for sensing in vivo conditions in the gastrointestinal (GI) tract, such as, temperature, pH or pressure. Ingestible imaging devices can be used for imaging the gastrointestinal tract. For example, a capsule comprising a sensor, such as an image sensor, may be ingested and moved passively through the small intestine by peristalsis while imaging or otherwise sensing the small intestine. However, passive movement of objects through larger body lumens, such as the large intestine, may be slower and unpredictable. The large intestine, or colon, whose main function is to remove much of the water from the stool and to store the stool, begins with the cecum, a small saclike evagination, then continues with the ascending colon, from the appendix in right groin up to a flexure at the liver, transverse colon, liver to spleen, descending colon, spleen to left groin, then sigmoid (S-shaped) colon back to midline and anus. The colon has three longitudinal muscle bands whose actions assist movement through the colon.
It is sometimes advantageous to move objects through the colon independently of the natural action of the colon muscles. For example, delivery of a medicament to a specific location in the colon may be time dependant and cannot rely on the natural movement in the colon. Also a device for imaging the colon might benefit from being actively moved through the colon so as to efficiently view the colon.
Current methods of moving objects, especially imaging devices, through the colon involve the use of endoscopes, typically colonoscopes, which are expensive and inconvenient for patient use, and do not always enable to reach distal parts of the colon, such as the cecum and the right colon.